Analysis of the nature of injuries in victims of fall from height

Introduction

Falls from height are a significant problem both in the field of clinical medicine and forensic medicine. Depending on the country, falling is the third – or even second – leading cause of accidental or suicidal death, occurring mainly in urban environment [1, 2]. Falls from height result in diverse injuries which are conditional on a number of factors such as the height of the fall, age and body position of the victim, or features of the surface on which the victim falls [3]. There are also literature reports comparing injuries sustained during falls from height with injuries associated with head-on collisions of cars driving at considerable speed [3]; the injuries usually involve multiple organs.
The intuitive assumption is that the greater the height of the fall, the more extensive the body’s injuries and hence the higher mortality. However, the literature also comprises studies pointing out that the height of fall is not a reliable predictor of the severity of injuries. Also, the injury severity scores which are widely used in traumatology have been evaluated to determine their usefulness for the assessment of injuries caused by falls from height. It has been demonstrated that the higher the fall level, the higher the Injury Severity Score (ISS) [1, 4], however the scale does not make it possible to evaluate height accurately, since the majority of victims of falling frequently reach a high (often maximum) ISS score [2]. Another study has shown that a severe head or neck injury, defined as a score of 4 or more in the Abbreviated Injury Scale (AIS), is a strong predictor of mortality in falls from heights in excess of 6 metres [5]. However, attention is drawn to the fact that the above scores have their limitations. For example, ISS does not take into account multiple injuries in the same body region. Therefore, the development of a new scale, suited to the evaluation of specific injuries arising from falls and their correlation with height, seems warranted. Such a new scale would be particularly useful in the process of preparation of forensic expert opinions.

Aim of the study

The aim of the study was to assess the types and extent of injuries sustained by victims of fall from height depending on the height of fall.

Material and methods

Inclusion and exclusion criteria

The study comprised 338 bodies of victims of fatal falls from heights who were subjected to medico-legal autopsy at the Department of Forensic Medicine, Jagiellonian University Medical College, between 1995 and 2014.
The study group included cases in which victims fell from a known height expressed in floors. However, the study group excluded falls from an unknown height or height given in metres, as well as falls from the 11th floor or higher floors (because of a small number of cases – 22 in total). The individuals included in the analysis either died at the scene, during transport to the hospital or during hospitalization.

Data under analysis

Based on external and internal body examination reports, a set of data was collected for each case, including gender, age, body height, injury types and presence of alcohol or other intoxicants in blood. The analysis was performed for injuries to the brain, thoracic organs (lungs, pleura, heart, aorta, other major blood vessels, diaphragm), abdominal organs (spleen, liver, intestines, mesentery, omentum, kidneys, urinary bladder), thoracic or abdominal rupture, fractures of the skull, extremities, ribs and spine, and fractures of the scapula, clavicle and sternum (considered together).

Analysis of injuries and their mutual relationships

Based on data collected for the study, the degree of correlation was determined between individual injuries, injuries in total, age of victims and alcohol presence, and the height of fall; between age, body height and alcohol presence, and injuries; and between age and gender, and the height of fall. It was also determined whether there was a correlation between the occurrence of different injury types. Pearson’s r coefficient was adopted as a mathematical measure of correlation strength. The values of the coefficient r could range from 0 to 1 and from 0 to –1. Positive values of Pearson’s r coefficient indicate that the frequency of a given injury type increases with increasing height of fall. For negative values, the interpretation is the opposite, i.e. an increase in the height of fall is associated with a decreasing frequency of injuries. The absolute value of Pearson’s r coefficient provides information about the strength of a particular correlation under study, so values which are close to 1 or –1 are indicative of strong correlations.
The statistical significance levels adopted for the results were: *p < 0.05; **p < 0.025; ***p < 0.01 and ****p < 0.001. All calculations were performed with the Statistica v.12.0 software.

Results

The study involved an analysis of 338 cases (115 women and 222 men) of falls from different heights ranging from the 1st to the 10th floor. Alcohol and/or intoxicating agents were detected in the blood of 31.97% of all study subjects.

Injury types depending on height

The majority of injuries under analysis were present even in falls from the 1st and 2nd floors (Fig. 1A1–D) including potentially fatal injuries such as craniocerebral trauma, cardiac rupture or other major injury to the heart, aorta and lungs, rupture of the spleen and liver or cervical spine fractures [4].
The number and extent of injuries were found to increase along with the height of fall (Fig. 2). Every other person falling from the height of the 2nd floor suffered lung contusion and/or rib fractures. Half of all study subjects who fell from the height of the 5th floor sustained pelvic and/or skull fractures. Multiple skull fractures were identified in 50% of the victims who fell from the 9th floor. Half of the fatalities due to falling from the 6th floor were shown to have sustained fractures of long and short bones in the upper extremities, splenic ruptures, multiple liver ruptures and pleural ruptures. For falls from the 7th floor, the relationship was observed for pulmonary and cardiac ruptures or rupturing of major blood vessels. Falls from the height of the 8th floor resulted in open long bone fractures in 50% of all cases.
For 11 injuries, there was a confirmed correlation between the frequency of a specific injury and increasing height of fall (Table I). The relationships identified in the study are strong, with the r coefficient in the range from 0.67 to 0.85. They apply to the rupture of parenchymal organs (spleen, liver, kidney and lungs), bone fractures (pelvic and open long bone fractures) as well as the rupture of the heart and major blood vessels, the chest or the abdominal cavity. The strongest relationship was determined for aortic rupture (r = 0.85) and for upper extremity long bone fractures (r = 0.85).

Injuries occurring from a specific height

Bilateral kidney rupture and fractures of upper extremity small bones were shown to accompany falls from the 4th and 6th floors, respectively, and mesenteric injury – falls from the 3rd floor (Fig. 1C). Bilateral kidney injury was determined in 34 victims, mesenteric injury – in 37 victims, and fracture of upper extremity small bones – in 7 cases.

Relationships between injuries and victim age

The frequency of occurrence of different injury types was also assessed in relation to the age of victims of fall from height (Table II). The number of injuries was shown to rise with age – similarly to certain injury types including extensive cardiac injury and damage to major blood vessels, and fractures of ribs and thoracic spine. On the other hand, the frequency of lung contusion and skull fractures was shown to decrease with age. A negative correlation was also found for the height from which victims fall (Table II).

Discussion

The material collected for the purpose of the study was dominated by men, with a 2 : 1 men to women ratio. The result is consistent with the tendencies reported in the available literature [2, 3].
Falls from height are often associated with prior alcohol ingestion by the victim. The relationship is dual in nature. By adversely affecting the motor-spatial coordination, alcohol increases the risk of falling during work performed at heights, e.g. on construction sites. Furthermore, alcohol is often consumed shortly prior to suicidal attempts, with falls from height being the third most common means of suicide [1].
Also, there is a documented relationship between the coexistence of mental disorders and successful suicides, among which falls from height are most commonly chosen as a suicide method by individuals with schizophrenia and depression [6]. The two diagnoses were predominant in the material analyzed in the present study.
When falling, the human body positions itself in such a way that the centre of gravity is located in the lowest point. Consequently, the primary impact with the surface is made by the head and chest [3, 4]. The greater the height of fall, the more time the body has to assume this position, so the tendency is evident particularly in falls from great heights. In such cases, craniocerebral injuries are very severe and occasionally lead to excerebration [3].
In falls from moderate heights, the body usually lands on the chest. The rule accounts for the observed pattern of injuries which is dominated by pulmonary contusion, rib fractures and craniocerebral injuries [3, 4]. The three injury types are observed from the lowest fall heights analyzed in the present study (Fig. 1A–D). As the height of fall increases, the range of injuries to body organs and chest walls becomes much more diverse (Table I). Another, quite surprising, finding was an increase in the frequency of injuries affecting some of the abdominal organs. In the literature cited in the present study [4, 6], abdominal injuries represent a minority, however the authors emphasize that their presence is associated with increased mortality levels. The observed discrepancy is a result of differences in the study populations. The present analysis involved only deceased individuals, while the above-mentioned literature reports [4, 6] also include fall survivors. The material analyzed in the study shows that the frequency of injuries to the liver (single and multiple ruptures), spleen and kidneys increases in proportion to the height of fall. An interesting finding is that mesenteric and omental ruptures, as well as bilateral kidney ruptures, only accompany certain fall heights. Threshold values which are lower than those specified probably do not make it possible for the falling body to achieve an energy value necessary for sustaining such injuries. In falls from greater heights, the falling body has more time to position itself head down. As a result, the frequency of injuries to the abdominal organs decreases [4], which is notable in particular in mesenteric and omental ruptures, and bilateral kidney ruptures. The presence of these two injury types, similarly to fractures affecting the small bones of upper extremities, may therefore turn out to be a significant marker of fall height, however the proposal requires further verification.
The study also showed the injuries described above to frequently coexist with one another (Table III). Out of all studied relationships between different injury types and fall height, the strongest correlations were found for chest organ injuries. Due to anatomical proximity, similar correlations were also observed for upper extremity long bone fractures and injuries to the liver and spleen. Analogous relationships are also described in the available literature [3, 4, 6]. It must be noted, though, that some of the cases involved cardiorespiratory resuscitation attempts which may have given rise to additional injuries in the region of the sternum and adjacent rib sections. Such resuscitation injuries, unrelated to the mechanism of the fall, potentially complicate the interpretation of injuries in fatal fall victims.
The study data show that falls from the height of the 5th floor and higher are associated with a significant increase in the frequency of potentially fatal injuries such as extensive craniocerebral traumas, and liver and spleen ruptures [4]. The 5th floor is also a height from which an increased diversity and total number of injuries under study are observed (Fig. 2). In the literature, the 5th floor is reported as the threshold associated with a significant increase in death risk [3].
The strong correlation observed for the coexistence of open long bone fractures together with a group of injuries exhibiting a positive correlation with increasing height stems from the fact that an increase in height is linked to a marked increase in the frequency of different injuries. Brain injuries and multiple liver ruptures, similarly to thoracic or abdominal ruptures and multiple skull fractures, are recognized as life-threatening injuries [4] coexisting at falls from great heights (Table III). For them to arise, the falling body must be affected by a suitably large force [3].
Another observation relates to a decreasing frequency of thoracic organ injuries with a simultaneously rising frequency of craniocerebral injuries (Table III). The observation lends itself to a dual interpretation in conformity with the previously described relationship. For a falling body, the first point of contact with the surface is the chest, so thoracic organs absorb a considerable part of energy, cushioning the head of the victim. It must be noted, though, that immediately after hitting the surface the body continues its movement, which is seen at autopsy in the form of characteristic longitudinal skin abrasions. Probably at the same time, the victim’s head is tilted backwards in a way that is commonly observed during traffic accidents, resulting in a decreased frequency of craniocerebral injuries.
There are multiple reports pointing to a relationship between age and severity of injuries [3]. In elderly people, falling from a height lower than the 5th floor level referred to above carries a high risk of death because of their worse baseline physical status [3]. The observation was also confirmed by our analysis (Table II). It can be attributed to the presence of concomitant diseases developing with age as well as reduced tissue elasticity and capacity for regeneration [3]. The frequency of skull fractures is known to decrease with age. The observation is related to the ossification and thickening of skull bones that progress with age, and the reinforcement of sutural fusion which makes the skull more resistant to mechanical trauma. Elderly people were shown to have sustained cardiac or aortic wall rupture more frequently. The finding can probably be attributed to a reduced elasticity of these tissues (Table II). By the same token, there was an increased frequency of vertebral fractures, as well as fractures of the ribs and upper extremity long bones, which may be linked to age-related osteoporosis [3]. An increased susceptibility to bone fractures in the population contributes to an increased level of risk of death during falls from height [3].
The analysis presented in the paper will be used by the authors as a starting point for developing a medical score that would be helpful for evaluating the height of fall based on identified injuries, including:
• total number of injuries,
• injuries shown to be correlated in a statistically significant manner with an increasing height of fall (scores assigned to different injuries were calculated on the basis of appropriate Pearson’s r coefficients),
• injuries occurring from a certain threshold value (bilateral kidney injury and fracture of small bones in upper extremity).
In view of the multiplicity and diversity of injuries which occur in victims of falls from height, there is currently no score that would make it possible to determine the height of fall in a reliable and precise manner (with an accuracy to one floor). Inferences about the height of fall should be drawn on the basis of previously described general relationships. A useful indicator can be the presence of one of three specific injury types: mesenteric injury, bilateral kidney injury or fracture of small bones in upper extremity. The three injuries correspond to minimum fall heights: 3rd, 4th and 6th floors, respectively.

Conclusions

• Victims of falls from height are usually middle-aged individuals, men twice as often as women.
• One third of victims are under the influence of alcohol and/or intoxicants at the moment of the fall.
• The majority of injuries already occur as a result of falls from the height of the 1st floor, and as the height of fall increases, there is a rise in the frequency and multiplicity of injuries.
• Eleven injuries demonstrated a statistically significant correlation with the height of fall.
• Three injury types – mesenteric injury, bilateral kidney injury and fracture of upper extremity small bones – were shown to occur from the threshold height, which indicates the minimum height of falling.

The authors declare no conflict of interest.

Piśmiennictwo
References

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Adres do korespondencji
Magdalena E. Kusior
Studenckie Koło Naukowe Medycyny Sądowej
Collegium Medicum
Uniwersytet Jagielloński
Kraków, Polska
e-mail: magdalena.kusior9@gmail.com

Address for correspondence
Magdalena E. Kusior
Student Scientific Circle of Forensic Medicine
Jagiellonian University Medical College
Krakow, Poland
e-mail: magdalena.kusior9@gmail.com